The present invention relates to an electronic musical instrument, such as an electronic harmonica, having an input device driven by the flow of a breath.
Conventionally, an electronic harmonica is connected to external amplifiers, a power source, etc., by means of connecting cords extending from the harmonica housing so that musical sounds are produced from external loudspeakers. Although the harmonica housing may be compact in design, the use of the amplifiers, power source, loudspeakers and other external equipments lessens the portability of the instrument, constituting a hindrance to an easy musical performance.
An input device in the harmonica housing is provided with a contact mechanism which is driven by exhalation or inhalation. Since an electric circuit section including the contacts of the contact mechanism are subjected directly to the exhalation, the section is deteriorated in durability and is liable to contact failure. Various methods are proposed for driving the contact mechanism by breathing without causing the breath directly to touch the contacts. In any of these methods, however, the on-off operation of the contacts requires strong flows of breath, lowering the operating efficiency of the harmonica.